Purple Sweet Potato Bread

A few weeks ago I made one of my semi-regular trips to the Asian supermarket. I greatly enjoy shopping there; so much new stuff to try! I find the fresh fruit and vegetable section particularly appealing, as this is one of the few places in town where some of these foods can be found. On this particular trip, I found purple sweet potatoes — ones that were not just purple-skinned, but also purple-fleshed (I learned my lesson about checking the colour of the flesh before I bought them).

After peeling and boiling, this variety of sweet potato remained a vibrant deep purple. I served it a few times as a side-dish with dinner; it’s definitely not as sweet as the orange version I am most familiar with. I still had a few roots left over, so I decided to bake with them. I chose to use the Pumpkin Bread recipe from the Joy of Cooking (2006 edition, page 628). As per the book, “this loaf can be made with any cooked mashed squash, yams, or sweet potatoes”.

I was really hoping that the fantastic purple would come through, and I was happy to observe it in the batter, although it is diluted somewhat by the other ingredients.

Upon baking, though, I was highly disappointed by the colour. As it cooked, the loaf just turned brown, so much so that it is visually more-or-less indistinguishable from a pumpkin or orange sweet potato loaf. Obviously, some kind of chemical reaction had occurred.

Cracks on the surface of the loaf did reveal an odd green, so I decided to investigate. (I like “investigating” food, since this usually means I get to eat it.)

When sliced, it’s interesting how the outside turned brown, but the inside turned a dark, rotten turquoise. Even though the bread is only an hour or two old, it looked like it had been moldering in a damp cellar for years. Sadly, when I ate this bread, my taste buds and nose warred with my eyes; each slice was delicious and moist, and smelled delicous, but my eyes kept warning me that it was rotten, so I couldn’t enjoy it very much. (I had a similar experience with scrambled eggs turned green with food colouring for a meal of Green Eggs and Ham for a celebration of Dr. Seuss’ birthday on March 2nd a few years ago.)

I found it interesting how each slice different in its green shade, with the ones closest to the heel of the loaf being mostly brown, and the ones closer to the center of the loaf being mostly green, except for the edges.

All in all, this didn’t turn into the purple bread that I was hoping for, but as it stands, sweet potato bread made with purple sweet potatoes does have possibilities as Hallowe’en party food. That’s the one time of year that food that appears rotten while remaining safe and tasty is actually a triumph.